Assessing among-lineage variability in phylogenetic imputation of functional trait datasets

Phylogenetic imputation has recently emerged as a potentially powerful tool for predicting missing data in functional traits datasets. As such, understanding the limitations of phylogenetic modelling in predicting trait values is critical if we are to use them in subsequent analyses. Previous studies have focused on the relationship between phylogenetic signal and clade-level prediction accuracy, yet variability in prediction accuracy among individual tips of phylogenies remains largely unexplored. Here, we used simulations of trait evolution along the branches of phylogenetic trees to show how the accuracy of phylogenetic imputations is influenced by the combined effects of (1) the amount of phylogenetic signal in the traits and (2) the branch length of the tips to be imputed. Specifically, we conducted cross-validation trials to estimate the variability in prediction accuracy among individual tips on the phylogenies (hereafter “tip-level accuracy”). We found that under a Brownian moti...

系统发育插补（Phylogenetic imputation）近年来已成为预测功能性状数据集缺失数据的潜在有力工具。因此，若要将其用于后续分析，理解系统发育建模在预测性状值方面的局限性至关重要。以往研究聚焦于系统发育信号与分支水平预测精度之间的关系，但系统发育树中各个末端（tips）的预测精度差异仍未得到充分探索。在此，我们通过沿系统发育树分支进行性状演化模拟，揭示了系统发育插补的精度如何受到以下两个因素的联合影响：（1）性状中的系统发育信号量；（2）待插补末端的分支长度。具体而言，我们开展交叉验证试验，以评估系统发育树中各个末端的预测精度差异（以下简称“末端水平精度”）。我们发现，在布朗运动（Brownian motion）模型下……